U.S. patent application number 10/290392 was filed with the patent office on 2003-05-08 for distal protection device with local drug infusion by physician to maintain patency.
This patent application is currently assigned to Microvena Corporation. Invention is credited to Anderson, Kent D., Pavlovic, Jennifer L., Sukavaneshvar, Sivaprasad.
Application Number | 20030088211 10/290392 |
Document ID | / |
Family ID | 26966154 |
Filed Date | 2003-05-08 |
United States Patent
Application |
20030088211 |
Kind Code |
A1 |
Anderson, Kent D. ; et
al. |
May 8, 2003 |
Distal protection device with local drug infusion by physician to
maintain patency
Abstract
The present invention provides for a local drug delivery
mechanism for use with a protection device. An infusing device is
used to charge the drug into the catheter lumen toward a distal
portion of the lumen having a plurality of drug delivery exit
ports. The drug exits the ports into the patient's vascular system
and is able to flow toward a filter maintaining the patency of the
filter.
Inventors: |
Anderson, Kent D.;
(Champlin, MN) ; Pavlovic, Jennifer L.; (Afton,
MN) ; Sukavaneshvar, Sivaprasad; (Salt Lake City,
UT) |
Correspondence
Address: |
Lawrence M. Nawrocki
NAWROCKI, ROONEY & SIVERTSON, P.A.
Broadway Place East, Suite 401
3433 Broadway Street Northeast
Minneapolis
MN
55413
US
|
Assignee: |
Microvena Corporation
|
Family ID: |
26966154 |
Appl. No.: |
10/290392 |
Filed: |
November 7, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60337936 |
Nov 7, 2001 |
|
|
|
Current U.S.
Class: |
604/103.01 ;
606/200 |
Current CPC
Class: |
A61F 2230/0006 20130101;
A61F 2/013 20130101; A61M 25/007 20130101 |
Class at
Publication: |
604/103.01 ;
606/200 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. Apparatus for maintaining patency of an apertured device
implanted in a vessel in an animal body through which fluid flow
occurs, comprising: a patency maintenance drug introduction head,
positionable in the vessel proximate and upflow relative to the
device, for dispensing a patency maintenance drug; an elongate
member having a lumen therethrough, a distal end in fluid
communication with a cavity in said drug introduction head and a
proximal end remote from said introduction head and external to the
body of the animal; a reservoir at said proximal end of said
elongate member and in fluid communication with said lumen; and a
charger, associated with said reservoir, for volitionally urging
patency maintenance drug in the reservoir into and through said
lumen, into said cavity and into the vessel at said introduction
head.
2. The apparatus of claim 1 wherein said drug introduction head
includes a wall which defines said cavity therewithin, and wherein
said wall has a plurality of exit ports passing therethrough.
3. The apparatus of claim 2 wherein said reservoir and said charger
comprise a syringe mated to said elongate member at said proximal
end thereof.
4. The apparatus of claim 3 wherein said drug introduction head and
said elongate member are unitarily formed.
5. The apparatus of claim 4 wherein said drug introduction head
comprises an expanded portion of said elongate member.
6. A medical device, comprising: a protection member which permits
passage of a fluid therethrough, an elongate tubular member having
a head positioned proximate said protective member, said head
having a plurality of exit ports for delivering a drug to said
protective member to induce continued patency of said protective
member and a charger for remotely inducing delivery of the drug
through said exit ports.
7. The medical device of claim 6, wherein said protective member is
a filter.
8. The medical device of claim 7, wherein said filter is expandable
about a hostwire.
9. The medical device of claim 7, wherein said filter has a
hostwire extending within said tubular member.
10. A device for delivering a drug to a distal protection device to
maintain patency thereof, said device comprising a tubular member
having a wall, a proximal end, a distal end and a lumen, defined by
said wall, through said tubular member extending from said proximal
end to said distal end, said wall having an exterior surface, said
tubular member having a plurality of apertures formed through said
wall proximate said distal end of said tubular member and allowing
flow of the drug from said lumen to the exterior of said wall
proximate and at a location up-flow of the distal protection
device, and a charger mounted to said tubular member remote from
said apertures and external to a body of a patient to whom the drug
is to be delivered, for volitionally inducing flow of the drug
through said apertures.
11. The device according to claim 10, wherein said plurality of
apertures are spaced fully around said wall.
12. The device according to claim 10, wherein said wall has an
axial dimension, and wherein said plurality of apertures are spaced
along at least a portion of said axial dimension.
13. The device according to claim 12, wherein said plurality of
apertures are formed in a spiral pattern along said wall.
14. The device according to claim 10, wherein a distal portion of
said wall is enlarged.
15. The device according to claim 10, wherein said drug is in a
liquid form, and wherein said device is constructed to channel and
deliver said drug.
16. The device according to claim 10, wherein said drug is infused
into said lumen of said tubular member.
17. A filter device, comprising: an expandable filter portion; and
a drug delivery portion including a tubular member having a wall
and having a first end, a second end and a lumen through said
tubular member extending from said first end to said second end,
said wall having an exterior surface and said tubular member having
a plurality of apertures formed through said wall to allow fluid
communication of a drug from said lumen to the exterior of said
wall.
18. Apparatus for delivering a drug to a distal protection device
to maintain patency thereof, said apparatus comprising a tubular
member having a wall, a proximal end, a distal end and a lumen,
defined by said wall, through said tubular member extending from
said proximal end to said distal end, said wall having an exterior
surface, said tubular member having a plurality of apertures formed
through said wall proximate said distal end of said tubular member
and allowing flow of the drug from said lumen to the exterior of
said wall proximate the distal protection device, and a charger
mounted to said tubular member remote from said apertures, for
inducing flow of the drug through said apertures.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a regular application filed under 35 U.S.C.
.sctn.111(a) claiming priority, under 35 U.S.C. .sctn.119(e) (1),
of provisional application Serial No. 60/337,936, previously filed
Nov. 7, 2001 under 35 U.S.C. .sctn.111(b).
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to medical devices
for filtering or removing matter from within a vascular system and
the delivery of drugs to maintain continued filter patency. More
specifically, the present invention relates to protective measures
employing a drug delivery system for facilitating patency of the
medical device. This device also relates to any other
interventional applications where patency must be maintained. This
includes such apparatus as stents, grafts, vessel liners and flow
diverters.
[0004] 2. Description of Related Art
[0005] Protective devices, generally, include an expandable filter
attached to a hostwire. Protective devices are often employed in
interventional cardiology/radiology applications to allow the flow
of fluid, such as blood, while preventing the passage of
particulate matter, such as emboli. Protective devices are often
referred to as distal protection devices where the term `distal`
refers to the positioning of the device distal to a lesion or
treatment site, with respect to fluid flow in a vessel. The filter
portion of existing protection devices may include such items as
braided meshes, woven fabrics, perforated films, a plurality of
crossing wires, electrospun polymers and any other configuration
suitable for filtering.
[0006] The performance of the protective device requires that the
filter maintain patency. Patency is defined as the ability of the
filter to allow the passage of fluid. Patency may refer to the
patency of a filter at a specific point in time and/or the amount
of time that a filter is able to maintain fluid flow. When used in
a vascular system, the patency of the filter decreases over a
period of time. As the pore size of the filter decreases, the
patency will decrease relative to the patency for a greater pore
size. For example, in some filters, when the maximum pore size is
100 um there may be pores ranging in size from 20 um or less. Such
a fine pore size may cause a filter to become occluded by debris.
Pores below a crucial pore size may also become occluded by
formation of an impermeable fibrous sheet that may close off flow
through the pore.
[0007] The current art utilizes three different mechanisms for
facilitating patency.
[0008] The first mechanism used in the art involves the use of
coatings on the filter to prevent blood clotting. Such coatings
include anti-coagulants or anti-thrombogenic or anti-platelet or
other such drugs, such as Heparin. Even with such coatings, the
patency of the filter is limited because the drug coating is
eventually overcome by clotting forces in the blood. Thus, this
mechanism results in the patency beginning to decrease as soon as
the coating contacts the clotting agents of the blood, and it is
only a matter of time before filter patency is reduced or
eliminated by the clotting agents.
[0009] Two other mechanisms used to provide for increased filter
patency include dipping the filter in an anti-coagulant such as a
Heparin solution, or a systemic use of drugs such as a IIb/IIIa
inhibitor. Even with dipping in Heparin, the patency of the filter
will deteriorate over a relatively short period of time. Problems
with systemic use of drugs may manifest themselves as excessive
patient bleeding.
SUMMARY OF THE INVENTION
[0010] The present invention is drug delivery system for
facilitating the patency of a filter positioned within a patient's
vascular system. An embodiment of the present invention includes a
tubular member having a side wall defining an inner lumen. A distal
portion of the lumen has a plurality of exit ports extending
through the side wall. The proximal end of the tubular member is
able to mate with a drug loaded syringe. The drug is charged into
the lumen to the distal portion of the tubular member where the
drug is able to exit through the exit ports.
[0011] The tubular member may be secured to a hostwire, proximal to
the expandable filter of the protection device. The expandable
filter is secured to the hostwire.
[0012] In use, the protection device is deployed in a patient's
vascular system. The drug is delivered into the tubular member and
is infused into the patient's vascular system through the exit
ports of the tubular member. The drug enters the patient's blood
within the patient's blood vessel and flows toward the filter for
local delivery of the drug for maintaining filter patency.
Interventional devices such as PTCA catheters or stents are
advanced over the tubular member to a region of interest. The
region of interest is treated and emboli released are captured from
the bloodstream by the filter. The treatment device, filter, and
emboli are removed from the region of interest.
[0013] Local drug infusion helps to maintain patency of the filter
while blood is flowing through the filter. Local drug infusion
provides the anti-coagulation effects of the drug in a local
concentration where needed, to maintain filter patency while
minimizing the possible side effects (i.e. excessive bleeding) that
the drug could cause if used systemically. Generally, the drug is
delivered upstream of the filter, proximal to the filter, and
allowed to flow distally, through the filter with the blood.
DESCRIPTION OF THE DRAWING
[0014] FIG. 1 is a side view of the present invention, some
portions broken away.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention, illustrated in FIG. 1, is a distal
protection apparatus 15 having the capability of local delivery of
a drug to an expandable filter 12 positioned in a lumen 20 in a
patient's body. A tubular member 81 extends from a proximal end 83
to a distal end 79. The tubular member 81 has a wall 76 defining a
lumen 72 through member 81. The distal end 79 of the tubular member
81 comprises a portion 80 having a cavity defined therewithin and
has a plurality of exit ports 74 in the wall 76, thus forming a
drug delivery portion or head 80 of the distal protection apparatus
15.
[0016] Distal protection apparatus 15 is illustrated having a
hostwire 14 to which is mounted an expandable filter 12 at a distal
end 13 of the hostwire 14. The distal end of the tubular member 81
is attached to the proximal end of hostwire 14.
[0017] The present invention is intended for use in a patient's
vascular system. In operation, an infusing device, such as a
syringe 64, is filled with a drug for facilitating filter patency
within a blood vessel. The syringe 64 is mated to the proximal end
83 of the distal protection apparatus 15, and the drug is charged
into the lumen 72. Optionally a removable hub can be provided at
the proximal end 83 of the apparatus 15. The drug flows toward the
distal end 79 and exits the lumen 72 through the exit ports 74. As
the drug is released from the drug delivery portion 80 of the
distal protection apparatus 15, the drug is locally delivered into
the blood of a patient's vascular system and is carried toward the
filter 12 for maintaining patency of the filter 12.
[0018] Local drug infusion helps to maintain patency of the filter
12 to ensure blood is flowing through the filter. Local drug
infusion provides the anti-coagulation effects of the drug in a
local concentration, where needed, to maintain filter patency while
minimizing possible side effects (i.e., excessive bleeding) that
the drug could cause if used systemically.
[0019] The infusing device 64 in FIG. 1 is shown as a syringe. The
drug is loaded in the infusing device 64 for introducing the drug
into the lumen 72. The drug delivery portion 80 has a first,
proximal end 85 at which the dispensing portion of the tubular
structure 81 mates with delivery portion 80 for dispensing the drug
from lumen 72 which is defined by elongate tubular structure 81. It
will be understood that portion 80 can be enlarged, constant, or
reduced in diameter as compared to dispensing portion of tubular
structure 81.
[0020] As illustrated, the delivery ports 74 may be a plurality of
apertures spaced about the wall 76 of the drug delivery portion 80.
The apertures 74 form channels from the interior of portion 80 to
the exterior of the wall 76. This allows the drug to be delivered
from within the lumen 72 to the exterior of portion 80. As the drug
is released, it is delivered to the area of filter 12 of the distal
protection apparatus 15. The drug is then able to facilitate
continued patency of filter 12.
[0021] In operation, a physician fills the syringe 64 with the
appropriate drug and mates the syringe to the proximal end 83 of
the distal protection apparatus. The drug is then dispensed from
the syringe 64 into the lumen 72.
[0022] An intended use for the present invention is in a patient's
body such as during a medical procedure. For example, the device
can be used in a patient's vascular system such as a blood vessel.
The filter 12 can be deployed within the blood vessel so as to
filter emboli and particulate matter entrained in the blood of the
patient.
[0023] The physician may position the distal protection apparatus
15 within the patient's vascular system and deploy the filter 12
such that the periphery of the filter 12 engages the wall of the
blood vessel within which the device is deployed. Syringe 64 with a
predetermined amount and type of drug may be mated to the proximal
end 83 of the tubular structure 81 so as to allow charging of the
drug into the apparatus 15. The drug is dispensed from the syringe
64 into the lumen 72. Once the drug is introduced into the lumen
72, the drug is infused through the delivery ports 74 in wall 76 of
the lumen 72. The drug is then delivered into the bloodstream and
is able to flow to the filter 12. The local release of the drug
near the filter 12 allows for increased filter 12 patency even with
a filter 12 having a smaller pore size.
[0024] A treatment device is introduced over the tubular member 81
and a region of interest is treated. For example, a PTCA catheter
may be used to dilate a stenosis, a stent may be delivered and
expanded within a lesion, or a thrombectomy device may be advanced
to remove thrombus. Optionally, a drug may be infused periodically
during or before the procedure to help maintain patency.
[0025] Typically the filter would be recovered by withdrawing the
apparatus into a catheter, such as a delivery catheter or a balloon
catheter, following the procedure.
[0026] The drug delivery may also prevent or remove thrombi or
buildup within the blood vessel that is captured in the filter 12
or collected near filter 12. Such build-up could otherwise remain
within the blood vessel after the filter 12 has been retracted or
removed from the blood vessel.
[0027] Other structure for delivering the drug include a pump
powered by induction, a screw drive and an elastomer drive,
preferably used in conjunction with the syringe 64.
[0028] The delivery ports 74 may be spaced in a variety of
arrangements in the wall 76. For example, the delivery ports 74 may
be spaced circumferentially at various positions along the axial
dimension of the wall 76, patterned along the length of the wall
76, spaced so as to wind about the length of the wall 76, and any
combination or other means of spacing, random or ordered, so as to
provide delivery of a drug from the lumen 72.
[0029] The spacing and sizing of the apertures 74 may be configured
to control the rate of infusion of the drug into the blood vessel.
The apertures 74 may have a predetermined size and spacing that
allows for a slower or faster relative rate of infusion.
Controlling the rate of infusion may lessen the shear stresses on
blood flowing toward the filter 12. A lesser shear stress is
preferable over a high pressure drug delivery that may create an
accelerated flow pattern which could be detrimental to flow
dynamics surrounding the filter 12.
[0030] The delivery rate and concentration of the drug may also
play a role in the efficacy of operation. For example, a lower
concentration drug solution can be delivered at a faster rate, or a
higher concentration drug solution can be delivered at a slower
rate.
[0031] After the drug is delivered through the delivery ports 74,
it is infused within the fluid flowing external to portion 80. For
example, if the tubular member 81 is positioned within a
bloodstream, the drug will become infused within the blood stream.
As the blood stream is flowing toward the filter 12, the filter 12
being downstream, the drug will likewise be delivered to the filter
12 from an upstream location. Infusing the drug upstream from the
filter 12 and allowing it to flow to the filter 12 may also effect
delivery of the drug to local stasis areas in the vicinity of the
filter 12 where it can minimize and/or prevent clotting and
coagulation. This may result in flushing of loose, partially
adherent emboli that may otherwise become dislodged during or after
filter 12 removal.
[0032] The shape and size of the filter 12 are not critical to the
efficacy of the present invention. The filter 12 may assume a
variety of configurations such as a basket, a windsock, a flat
shape and any number of elongated shapes. The filter 12 may have a
cover. The filter 12 merely must perform the function of preventing
the passage of particulate material of a predetermined size. The
present invention addresses the delivery of a drug to a filter 12
to facilitate filter patency and contemplates the drug delivery
system disclosed herein as functioning with a variety of filter
sizes, shapes and configurations.
[0033] The filter 12 may be attached to the distal portion of a
hostwire 14, as shown. The hostwire 14 may extend through the lumen
72 containing the drug. Alternatively, the hostwire 14 may have a
drug delivery portion 80 for containing and delivering the drug
therefrom.
[0034] Possible drugs to be used in the present invention include
IIb/IIIa inhibitors and any other such anti-platelet agent,
anti-coagulant, lytic, and thrombus-stabilizing agent or any other
such drug, such as Heparin, Integrilin or Aggrastat, or drug
combinations for preventing occlusions to the filter during a
medical procedure. Such drugs help to maintain filter patency even
with reduced filter pore size without negative effects of systemic
drug administration such as excessive bleeding.
[0035] The infusion capabilities of the present invention may also
provide the physician or operator the ability to take a diagnostic
blood sample at the filter 12 to assess platelet activity and
thereby assist in the determination of the appropriate drug or drug
combination to administer. Apparatus for determining coagulation
activity of blood and the response of a patient's blood to a
platelet inhibitor are known to those in the art. A physician could
obtain samples by pulling a vacuum on the drug delivery lumen 72
such as by pulling back on an empty syringe.
[0036] The present invention may include a relatively stiff yet
flexible tube such as a hypotube with a plurality of weep holes 74.
The tube could be metallic (e.g. Nitinol or stainless steel),
liquid crystal composite, carbon fiber and composites of same,
other composites, ceramic, or other material known in the art.
Alternatively, the entire tubular member 81, including the drug
delivery portion, could be of a flexible material with a plurality
of weep holes 74 at a distal end 79 thereof.
[0037] It will be understood that this disclosure, in many
respects, is only illustrative. Changes may be made in details,
particularly in matters of shape, size, material, and arrangement
of parts without exceeding the scope of the invention. Accordingly,
the scope of the invention is as defined in the language of the
appended claims.
* * * * *